Most submersible pumps located at service stations or other fueling areas are set into the underground storage tank and the pump head and associated piping and electrical fittings are then exposed to the ground without secondary containment, as shown in FIG. 1. This area is unprotected and any accidental releases will directly result in contamination of soil and/or groundwater.
A secondary containment system is a system that collects and contains fluids that leak out of another and primary containment system. For example, a primary containment system may store, pump and deliver hydrocarbon fuels, such as gasoline and diesel oil, at a fueling station. A secondary containment system collects and contains that same fuel if a primary tank, pump or delivery pipe should rupture or otherwise spill the gasoline. A secondary containment system also catches fuel that spills when a fill tube runs over while a fuel storage tank is being filled, for example. While the invention is described hereinafter in connection with a hydrocarbon fuel filling station storage and delivery system, it should be understood that the invention may also be used to protect any other suitable primary containment system.
With the advent of more stringent environmental regulation, it is important to attempt to contain any fuel spillage and prevent passage of such spillage to the ground, where absorption can require removal an treatment of the contaminated ground material. Hence, it is highly desirable to provide a secondary containment system for spillage from a submersible pump.